Activated Prothrombin Concentrate for Patients with Factor VIII Inhibitors

Abstract

Activated prothrombin concentrate, a complex containing prothrombin, factors VII, IX, X, and XI, was used successfully for the treatment of hemorrhagic episodes in eight patients with factor VIII inhibitors. Six had hemophilia A, and two were women with acquired inhibitors. Partial thromboplastin times decreased immediately after infusion of the complex, and remained low for as long as 24 hours. Prothrombin times decreased also, whereas factor X rose 200 to 300 per cent, and factor VII levels increased by as much as 2000 per cent. Although thrombotic complications can occur after infusions of regular prothrombin complex preparations, none developed with the activated concentrate. Fibrin split products were found in two patients in titers of 1:5 and 1:40. This complex appears to offer effective control of severe hemorrhage in patients with factor VIII inhibitors. (N Engl J Med 291:164–167, 1974)